1. Field of the Invention
The present invention relates to selectors for selecting audio signals output from multiple audio devices. The present invention also relates to amplifier devices for amplifying audio signals selected by selectors.
The present application claims priority on Japanese Patent Application No. 2007-121876, the content of which is incorporated herein by reference.
2. Description of the Related Art
Conventionally, audio amplifiers have been connected to various types of audio devices such as CD players, CD-DA (i.e. Compact Disk Digital Audio) players, DVD (i.e. Digital Versatile Disk) players, television receivers, radio receivers, broadcast receivers, and tuners, in which audio signals are appropriately selected and amplified. Users press playback buttons of audio devices so as to issue playback instructions, and they also operate input select controls (e.g. input select dials and remote control buttons) so as to selectively activate audio devices receiving playback instructions.
When users intend to listen to desired audio contents, it is necessary for users to perform troublesome operations for specifically selecting audio devices and audio amplifiers.
Some audio devices are designed to output audio signals together with control signals indicating present statuses of audio devices (e.g. playback modes and stop modes). Some audio amplifiers are designed to recognize control signals output from audio devices, thus avoiding troublesome manual operations by users. Various documents such as Patent Document 1 teach various types of audio amplifiers having the aforementioned functions.
Patent Document 1: Japanese Unexamined Patent Application Publication No. 2000-339840.
The audio amplifier of Patent Document 1 needs control signals other than audio signals in order to automatically select desired audio signals suited to user's preference; hence, it cannot handle other audio devices incapable of outputting control signals.